<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
<h1>注册页面</h1>
  <input type="text" v-model="user.username" @blur="f" placeholder="用户名">{{info}}<br>
  <input type="password" v-model="user.password" placeholder="密码"><br>
  <input type="text" v-model="user.nickname" placeholder="昵称"><br>
  <input type="button" value="注册" @click="reg">
</div>
<script src="https://cdn.bootcdn.net/ajax/libs/axios/0.21.1/axios.min.js"></script>
<script src="https://cdn.staticfile.org/vue/2.2.2/vue.min.js"></script>
<script>
    let v = new Vue({
        el:"body>div",
        data:{
          user:{
            username:"",
            password:"",
            nickname:""
          },
          info:""
        },
        methods:{
          reg(){
            axios.post("/reg",v.user).then(function (response) {
                if (response.data==1){
                    alert("注册成功!");
                    v.info="注册成功!";
                }else {
                    alert("用户名已存在!");
                    v.info="用户名已存在!";
                }
            })
          },
          f(){
            axios.get("/check?username="+v.user.username).then(function (response) {
                alert(response.data);
                v.info=response.data;
            })
          }
        }
    })
</script>
</body>
</html>